Mexico. Antonio de Barroco to José Miguel Sanchez Navarro. Speaks of doctorship being conferred on Letona, 1791, July 6:

Mexico. Antonio de Barroco to José Miguel Sanchez Navarro. Speaks of doctorship being conferred on Letona, 1791, July 6:, Box: 1, Item: 3428. Sánchez Navarro Collection of Documents for a History of Texas and Coahuila, 30605850. Benson Latin American Collection, The University of Texas at Austin. https://archives.lib.utexas.edu/repositories/4/archival_objects/300786 Accessed September 27, 2026.